Resilient channel and broadcast modulation

ABSTRACT

Methods, systems, and apparatuses can provide a plurality of RF channels and outputs using digital modulation and combining. In various examples, generation of digital IQ packetized data in combination with digital switching can increase the number of RF modulated channels, optimize broadcast transmission and/or provide transmission resiliency.

TECHNICAL FIELD

This disclosure relates to the generation of digitally modulated radiofrequency (RF) channels and outputs for resilient unicast and broadcasttransmission.

BACKGROUND

There has been an industry trend from analog to digital modulation incommunication systems. Some of the benefits of digital modulationinclude more robust communication, ability to introduce security throughencryption/de-encryption, the ability to multiplex multiple forms ofdata (e.g., data, voice, video . . . ) and lower implementation costs,among others.

Digital modulation can be used to transfer digital serial data over anRF passband waveform. Modulation techniques include, but are not limitedto, quadrature phase shift keying (QPSK), differential quadrature phaseshift keying (DQPSK), frequency shift keying (FSK), minimum shift keying(MSK), quadrature amplitude modulation (QAM) and differential quadratureamplitude modulation (DQAM). Digital modulation is used in wireless andwired communication systems. Cellular, satellite, terrestrial andbroadband cable systems represent examples of communication systemsimplementing digital modulation. Modulation can be implemented throughIQ generation (e.g., channel coding) and digital modulation (e.g., RFsynthesis or direct digital synthesis). The “I” represents the in phasecomponent where the “Q” represents the quadrature component. IQ data canresult in an IQ stream that can be switched to provide resiliency andsupport broadcast transmissions from a single generation point. In oneimplementation, IQ data can be packetized for switching while otherimplementations switching can be performed on non-packetized IQ data.One or more IQ streams can be combined in one implementation of adigital modulator to optimize the number of RF channels supported.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram illustrating an exemplary network environmentoperable to provide a plurality of RF modulated channels and outputs.

FIG. 2 is a block diagram illustrating one implementation of an edgemodulator device.

FIG. 3 is a block diagram illustrating one implementation of acontroller device for use in an edge modulator.

FIG. 4 is a block diagram illustrating one implementation of an IQgenerator device for use in an edge modulator.

FIG. 5 is a block diagram illustrating one implementation of a modulatorsubsystem for use in an edge modulator.

FIG. 6 is a block diagram illustrating one implementation of an edgemodulator where an IQ generator can be used to increase the number of RFmodulated channels.

FIG. 7 is a block diagram illustrating one implementation of an edgemodulator where a IQ generator can be used to generate broadcast data.

FIG. 8 is a block diagram illustrating a configuration where one or moreedge modulators can provide one or more RF modulated channels.

FIG. 9 is a block diagram illustrating a configuration where one or moreedge modulators can continue to provide one or more RF modulatedchannels upon a failure.

FIG. 10 is a block diagram of an example packet processor that can beused in an edge modulator device.

Like reference numbers and designations in the various drawings indicatelike elements.

DETAILED DESCRIPTION

Digitally modulated channels can be directly synthesized to an analog RFpassband for transmission in a communication system. The number ofdigitally modulated channels can be limited by the digital modulationtechnology used in the implementation. To increase the number ofmodulated channels for transmission in a communication system one ormore RF passbands can be combined in the analog domain. Thecommunication system can be optimized through digitally combiningmodulated channels in the digital domain as opposed to the analogdomain. The ability to reuse digital broadcast modulated channels canprovide system optimization. Furthermore, resiliency to decreasecommunication service outages can further optimize a communicationsystem.

FIG. 1 is a block diagram illustrating an exemplary network environmentoperable to provide a plurality of RF modulated channels and outputs. Insome implementations, a headend 105 can provide video, data and/or voiceservice(s) to customer premise equipment (CPE) devices 110 a-d to one ormore subscribers through access network 115. The headend 105 can includeone or more devices such as edge modulator(s) 120. The edge modulator(s)120 can operate to facilitate transmission of signals from digital videosource(s) 125, data source(s) 130 and voice source(s) 135 through accessnetwork 115 to CPE devices 110 a-d. In various implementations, digitalvideo source(s) 125, data source(s) 130 and voice source(s) 135 canprovide communications through one or more networks internal to theheadend and/or one or more networks external to the headend (e.g., oneor more extranets, the Internet, etc.). For simplicity, onlycommunication from the sources 125, 130 and 135 will be described. Itshould be understood that communication with CPE devices 110 a-d canoccur in both directions.

The edge modulator(s) 120 can receive data signals from digital videosource(s) 125. Video source(s), for example, can provide MPEG transportstreams generated by video streaming applications (e.g., Video onDemand). The edge modulator(s) 120 can receive data signals from datasource(s) 130 or network nodes (not shown) in packet form. Voicesource(s) can include VoIP data and can be provided to edge modulator(s)120 from a public switched telephone network (PSTN) (not shown). Video,data and voice data sources 125, 130 and 135 can operate, for example,using Gigabit and/or 10 Gigabit ethernet protocols, sending data packetsto edge modulator(s) 120. The video source(s) 125, data source(s) 130and voice source(s) 135, can be packets from a CMTS (not shown).

In some implementations, the edge modulator 120 can modulate digitalsignals and generate one or more channels on one or more RF outputs fortransmission to subscribers. The RF output(s) can include, but are notlimited to, data, voice and video streams for transmission to a combiner(not shown), which can combine multiple RF outputs onto coax, opticalfiber, wireless or other physical layers for transmission to one or moreCPE devices 110 a-d via the access network 115.

CPE devices 110 a-d can include, display and input/output devices suchas televisions, personal computers (PC), video cameras, security systemsand mobile phones. The interface to access network 115 can be integratedinto CPE devices 110 a-d or can be provided by separate device(s).

FIG. 2 is a block diagram illustrating one implementation of an edgemodulator device 120. The edge modulator device 120 and/or elementsprovided within the edge modulator device 120 can be used in wired orwireless communication systems. The edge modulator 120 can reside in aheadend (e.g., headend 105 of FIG. 1), wireless base station, and/or canbe distributed elsewhere in the communication system. Someimplementations can include an edge modulator device 120, and/orelements of, in a fiber node (not shown) of an HFC network (e.g., accessnetwork 115 of FIG. 1).

The edge modulator device 120 can include one or more packet basedinterface(s) 210 and can receive data, voice and video packet based datastreams. Some implementations can include the data, voice and videopackets combined in one or more physical interface(s) 210. The packetinterface(s) 210 can be provided by gigabit Ethernet or other interfacessuch as 10-gigabit and passive optical network technologies.Implementations of the packet based interface(s) 210 can be copper orfiber based. The edge modulator device 120 can include one or morepacket based backup interfaces(s) 220 providing resiliency in the eventof a failure. The edge modulator device 120 can provide one or more RFoutput(s) 270. Each RF output can contain one or more modulated channelsfor transmission on the access network.

The controller 230 can be operable to implement the components of thepacket interface(s) 210 which can include physical, link, network,transport and application layer components. Support of network,transport and application layer components can be involved in networkmanagement. For example, SNMP based network management of the edgemodulator 120 can be implemented. The edge modulator 120 can alsoinclude one or more IQ generators 240 a-b and modulator subsystems 250a-b.

The IQ generators 240 a-b can be operable to receive video, data andvoice information from controller 230 and perform a digital process ofIQ generation (e.g, channel coding). Multiple modulation types can beimplemented by IQ generators 240 a-b to include, for example, quadraturephase shift keying (QPSK), differential quadrature phase shift keying(DQPSK), frequency shift keying (FSK), minimum shift keying (MSK),quadrature amplitude modulation (QAM) and differential quadratureamplitude modulation (DQAM), among any other suitable modulation scheme.IQ generators 240 a-b can encapsulate the IQ components in a digitalpacket stream to be provided to controller 230. In other implementations(not shown) IQ generators 240 a-b can provide an IQ stream to controller230 in a non-packetized form.

The modulator subsystems 250 a-250 b can be operable to receive video,data, voice and IQ data from controller 230 generating a modulatedsignal (270) for transmission on access network (e.g., access network115 of FIG. 1.). In one implementation, IQ data can be encapsulated in apacket. In other implementation the IQ data can be non-packetized.

FIG. 3 is a block diagram illustrating one implementation of acontroller device for use in an edge modulator. The controller 230 caninclude switch 310 and packet processor 320. Switch 310 can route video,data and voice packets from video, data and voice interface(s) to packetprocessor 320. Packet processor 320 for example, can perform packetprocessing such as MPEG framing, downstream scheduling, QOS, policing,filtering and rate-shaping. The packet processor 320 can includeinterfaces (not shown) to switch 310, IQ generator(s) (e.g. IQ generator240 a-b in FIG. 2) and modulator subsystem(s) (e.g., modulatorsubsystem(s) 250 a-b in FIG. 2) providing configuration and controlfunctions. In addition, packet processor 320 can implement a networkmanagement application.

After packet processing, switch 310 can route video, data and voiceinformation from packet processor 320 to IQ generator(s) (e.g., IQgenerators 240 a-b of FIG. 2) through interfaces 330 or modulatorsubsystems (e.g., modulator subsystem 250 a-b of FIG. 2) throughinterfaces 340. Switch 310 can also route data from IQ generator(s) andmodulator subsystem(s) and/or backup interface(s) (backup interface(s)220 in FIG. 2.). The interfaces 330 and 340 between switch 310, IQgenerator(s) and modulator subsystem(s) can be implemented, but notlimited to a XAUI interface supporting packetized IQ data or anon-packetized interface.

FIG. 4 is a block diagram illustrating one implementation of an IQgenerator device for use in an edge modulator. The IQ generator device240 can include media access controller 410, channel coding 420 and IQencapsulation 430. The IQ generator 240 can receive video, data andvoice information from a switch (switch 300 in FIG. 3).

The media access controller can provide control and processing forinformation received from and sent to the switch. Media accesscontroller provides digital information from and to channel codingdevice 420.

Channel coding device 420 can be implemented to perform digital IQchannel coding including forward error correction (FEC) interleaving,convolutional encoding and symbol mapping for the access network. ITUJ.83 represents one example of an access network specification for abroadband network.

The IQ digital data from the channel coding device 420 can be packetizedby the IQ encapsulation device 430. Other implementations can includenon-packetized IQ data (not shown). The packetized IQ data can then besent to the switch by the media access controller 410. Media accesscontroller 410, channel coding 420 and IQ encapsulation can beimplemented as separate devices or integrated into a single device withFPGA, ASIC and/or other integrated circuit technologies.

FIG. 5 is a block diagram illustrating a modulator subsystem operable tobe used in an edge modulator. Modulator subsystem 250 can include mediaaccess controller 510, IQ decapsulation 520, channel coding (e.g.,channel coding 420 in FIG. 4), digital modulator 530, digital analogconvertor (DAC) 540 and physical layer 550. The modulator subsystem 250can receive video, data, voice and IQ information from the switch (e.g.,switch 310 of FIG. 3).

Media access controller 510 can provide video, data and voiceinformation to channel coding device 420 and IQ decapsulation device 520with IQ packets generated by IQ generator(s) (e.g., IQ generator(s) 240a-b in FIG. 2). In other implementations, Media access controller 510can provide non-packetized video, data and voice information (notshown). For packetized IQ data, the IQ decapusulation device 520 can beimplemented to de-packetize the IQ data and provide IQ digital data todigital modulator 530. Digital modulator 530 can receive IQ digital datafrom IQ decapusulation device 520 and the channel coding device 420.

Digital modulator 530 can perform channel shaping (Nyquist filters),channel combining (two or more IQ data streams) into channel blocks.Channel blocks can be upsampled and digitally modulated with a carrierfrequency and interpolated to the DAC 540 sample frequency. The digitalmodulator 530 can support one or more DACs (not shown). The DAC 540 canimplement direct analog synthesis of the digital input provided by adigital modulator 530. The physical layer 550 supports the physicallayer components of the access network. One or more physical layerdevice(s) 550 can be supported in various implementations with one ormore DACs 540.

FIG. 6 is a block diagram illustrating one implementation of an edgemodulator where an IQ generator can be used to increase the number of RFmodulated channels. Modulator subsystem 250 can receive video, dataand/or voice information from the switch (e.g., switch 310 of FIG. 3) oninterface 630. The maximum number of modulated channels provided by themodulator subsystem 250 can be limited by technology. In oneimplementation additional modulated channels can be provided by IQgenerator 240.

IQ generator 240 can receive video, data and or voice information fromthe switch (e.g., switch 310 of FIG. 3) on interface 610. The IQgenerator 240 can generate IQ data and send the data to modulatorsubsystem 250 as illustrated by connection 620. Connection 620represents a logical connection that can be physically performed by theswitch (not shown) through two interfaces.

Modulator sub-system 250 can be implemented to digitally combine the IQdata received on interface 620 with the video, data and/or voiceinformation received on interface 630 generating additional RF modulatedchannels for transmission on the access network.

FIG. 7 is a block diagram illustrating one implementation of an edgemodulator where an IQ generator can be used to generate broadcast data.Modulator subsystems 250 a-b can receive video, data and/or voiceinformation from the switch (e.g., switch 310 of FIG. 3) on interface(s)730 a-b for transmission on the access network with one or more RFoutputs. In some implementations, to support broadcast transmission, theIQ generator 240 can be used to generate broadcast IQ data. Thereby,information can be broadcast in nature, for example video source(s), canrequire the same video source to be transmitted to one or more modulatorsubsystems 250 a-b resulting in one or more RF outputs on the accessnetwork. Thereby, the implementation is optimized since the IQgeneration for broadcast traffic is only performed once for one or moreRF outputs.

IQ generator 240 can receive information broadcast in nature from theswitch on interface 710. The IQ generator can produce IQ broadcast dataon interface 720 to be routed by the switch (not shown) to one or moremodulator subsystems 250 a-b through the packet broadcast capabilitiesof the switch. Interface 720 is a logical representation of a connectionand can be provided by three physically separate interfaces between theIQ generator 240 and the switch and between the switch and the modulatorsubsystems 250 a-b.

Modulator subsystems 250 a-b can be implemented to digitally combine thebroadcast IQ data received on connection 720 with the video, data and/orvoice information received on interface 730 a-b generating RF modulatedchannels providing normal service and broadcast information fortransmission on the access network through one or more RF outputs.

FIG. 8 is a block diagram illustrating a configuration where one or moreedge modulators can provide one or more RF modulated channels. Externalswitch 810 can receive one or more packetized service streams fortransmission on the access network. The service streams can be providedby one (not shown) or more interfaces. The external switch 810 can be awell known commercially available router and/or switch. The externalswitch 810 can route the packetized service stream data to theappropriate edge modulator devices 120 a-b.

The edge modulators 120 a-b can be implemented to receive packetsthrough controller 230 for modulation with modulator subsystem 250providing modulated RF outputs. Combiner 820 can be used to implement RFcombining of the one or more modulated RF outputs from edge modulators120 a-b.

FIG. 9 is a block diagram illustrating a configuration where one or moreedge modulators can continue to provide one or more RF modulatedchannels upon a failure. The normal service packet data flow isillustrated by the dashed lines of FIG. 8. A service outage for servicestream 1 can occur upon failure of the modulator subsystem 250 in edgemodulator 120 a. One implementation to prevent a service outage isthrough the use of IQ generator 240, controller 230 and external switch810.

Upon failure detection of modulator subsystem 250 in edge modulator 120a the controller 230 can route the service stream 1 packet data to theIQ generator 240 in the edge modulator 120 a. The IQ generator 240 cangenerate IQ data and provide the IQ data to the controller 230 in edgemodulator 120 a. Controller 230 in edge modulator 120 a provides thepacketized service stream 1 IQ data to external switch 810 through thebackup interface (backup interface 220 in FIG. 2).

The external switch 810 can route the service stream 1 IQ data from edgemodulator 120 a to edge modulator 120 b through the backup interface(e.g, backup interface 220 in FIG. 2). Modulator subsystem 250 in edgemodulator 120 b can be implemented to digitally combine the servicestream 1 IQ data received on the backup interface) and the servicestream 2 packetized video, data and/or voice data received frominterface(s) (e.g., interface 210 in FIG. 2) by controller 230 in edgemodulator 120 b. The modulator subsystem 250 in edge modulator 120 b cangenerate RF modulated channels to combiner 820 for transmission on theaccess network.

FIG. 10 is a block diagram of a packet processor for a packet processor(packet processor 320 in FIG. 3). The packet processor device 1000 caninclude a processor 1010, a memory 1020, a storage device 1030, and aninput/output device 1040. Each of the components 1010, 1020, 1030, and1040 can, for example, be interconnected using a system bus 1050. Theprocessor 1010 is capable of processing instructions for executionwithin the system 1000. In one implementation, the processor 1010 is asingle-threaded processor. In another implementation, the processor 1010is a multi-threaded processor. The processor 1010 is capable ofprocessing instructions stored in the memory 1020 or on the storagedevice 1030.

The memory 1020 stores information within the device 1000. In oneimplementation, the memory 1020 is a computer-readable medium. In oneimplementation, the memory 1020 is a volatile memory unit. In oneimplementation, the memory 1020 is a non-volatile memory unit. Inanother implementation, the memory 1020 can be a combination ofcomputer-readable medium, volatile memory, and/or non-volatile memory.

In some implementations, the storage device 1030 is capable of providingmass storage for the device 1000. In one implementation, the storagedevice 1030 is a computer-readable medium. In various differentimplementations, the storage device 1030 can, for example, include ahard disk device, an optical disk device, flash memory or some otherlarge capacity storage device.

The input/output device 1040 provides input/output operations for thedevice 1000. In one implementation, the input/output device 1040 caninclude one or more of a wireless interface, HFC network interface, suchas, for example, an IP network interface device, e.g., an Ethernet card,a cellular network interface, a serial communication device, e.g., andRS-232 port, and/or a wireless interface device, e.g., and 802.11 card.In another implementation, the input/output device can include driverdevices configured to receive input data and send output data to otherinput/output devices, as well as sending communications to, andreceiving communications from various networks.

Implementations of the subject matter and the functional operationsdescribed in this specification can be provided in digital electroniccircuitry, or in computer software, firmware, or hardware, including thestructures disclosed in this specification and their structuralequivalents, or in combinations of one or more of them. Embodiments ofthe subject matter described in this specification can be implemented asone or more computer program products, i.e., one or more modules ofcomputer program instructions encoded on a tangible program carrier forexecution by, or to control the operation of, data processing apparatus.The tangible program carrier can be a propagated signal or a computerreadable medium. The propagated signal is an artificially generatedsignal, e.g., a machine generated electrical, optical, orelectromagnetic signal that is generated to encode information fortransmission to suitable receiver apparatus for execution by a computer.The computer readable medium can be a machine readable storage device, amachine readable storage substrate, a memory device, a composition ofmatter effecting a machine readable propagated signal, or a combinationof one or more of them.

The term “system processor” encompasses all apparatus, devices, andmachines for processing data, including by way of example a programmableprocessor, a computer, or multiple processors or computers. The systemprocessor can include, in addition to hardware, code that creates anexecution environment for the computer program in question, e.g., codethat constitutes processor firmware, a protocol stack, a databasemanagement system, an operating system, or a combination of one or moreof them.

A computer program (also known as a program, software, softwareapplication, script, or code) can be written in any form of programminglanguage, including compiled or interpreted languages, or declarative orprocedural languages, and it can be deployed in any form, including as astand-alone program or as a module, component, subroutine, or other unitsuitable for use in a computing environment. A computer program does notnecessarily correspond to a file in a file system. A program can bestored in a portion of a file that holds other programs or data (e.g.,one or more scripts stored in a markup language document), in a singlefile dedicated to the program in question, or in multiple coordinatedfiles (e.g., files that store one or more modules, sub programs, orportions of code). A computer program can be deployed to be executed onone computer or on multiple computers that are located at one site ordistributed across multiple sites and interconnected by a communicationnetwork.

The processes described in this specification are performed by one ormore programmable processors executing one or more computer programs toperform functions by operating on input data and generating outputthereby tying the process to a particular machine (e.g., a machineprogrammed to perform the processes described herein). The processes canalso be performed by, and apparatus can also be implemented as, specialpurpose logic circuitry, e.g., an FPGA (field programmable gate array)or an ASIC (application specific integrated circuit).

Processors suitable for the execution of a computer program include, byway of example, both general and special purpose microprocessors(general microprocessors being transformed into special purposemicroprocessor through the application of algorithms described herein),and any one or more processors of any kind of digital computer.Generally, a processor will receive instructions and data from a readonly memory, flash memory or a random access memory or all. The elementsof a computer typically include a processor for performing instructionsand one or more memory devices for storing instructions and data.Generally, a computer will also include, or be operatively coupled toreceive data from or transfer data to, or both, one or more mass storagedevices for storing data, e.g., magnetic, magneto optical disks, oroptical disks. However, a computer need not have such devices. Moreover,a computer can be embedded in another device, e.g., a mobilecommunications device, a telephone, a cable modem, a set-top box, amobile audio or video player, or a game console, to name just a few.

Computer readable media suitable for storing computer programinstructions and data include all forms of non volatile memory, mediaand memory devices, including by way of example semiconductor memorydevices, e.g., EPROM, EEPROM, and flash memory devices; magnetic disks,e.g., internal hard disks or removable disks; magneto optical disks; andCD ROM and DVD ROM disks. The processor and the memory can besupplemented by, or incorporated in, special purpose logic circuitry.

To provide for interaction with a user, embodiments of the subjectmatter described in this specification can be operable to interface witha computing device having a display, e.g., a CRT (cathode ray tube) orLCD (liquid crystal display) monitor, for displaying information to theuser and a keyboard and a pointing device, e.g., a mouse or a trackball,by which the user can provide input to the computer. Other kinds ofdevices can be used to provide for interaction with a user as well; forexample, feedback provided to the user can be any form of sensoryfeedback, e.g., visual feedback, auditory feedback, or tactile feedback;and input from the user can be received in any form, including acoustic,speech, or tactile input.

What is claimed is:
 1. An edge modulation system, comprising: acontroller operable to receive incoming digital data streams and processthe incoming digital data streams and direct the incoming digital datastreams for modulation; one or more I/Q generators operable to receivethe processed incoming data streams and to convert digital datacontained within the incoming data streams to in-phase and quadraturecomponents; one or more modulator subsystems operable to receive thein-phase and quadrature components from the controller and to modulatethe processed incoming data streams for transmission over an accessnetwork, wherein the modulator subsystem is further operable todigitally combine the in-phase and quadrature components with normalservice data received directly from the controller; wherein each of theone or more I/Q generators comprise: an I/Q generator media accesscontroller operable to provide control and processing for informationreceived from or destined for a switch in the controller; a channelcoding module operable to receive data from the I/Q generator mediaaccess controller, perform digital I/Q channel coding including forwarderror correction (FEC) interleaving on the data and provideconvolutional encoding and symbol mapping for the access network; and anI/Q encapsulation device operable to packetize I/Q digital data receivedfrom the channel coding module.
 2. The edge modulation system of claim1, wherein the controller comprises the switch operable to receivevideo, data and voice streams, the switch being operable to forward thevideo, data and voice streams to the one or more I/Q generators or oneor more modulator subsystems responsive to a packet processor.
 3. Theedge modulation system of claim 2, wherein the switch is furtheroperable to provide a backup interface operable to couple the edgemodulation system to an external switch.
 4. The edge modulation systemof claim 3, wherein the backup interface facilitates providing a backupI/Q generator to a second edge modulation system upon failure of one ormore components of the second edge modulation system.
 5. The edgemodulation system of claim 3, wherein the backup interface facilitatesproviding a backup I/Q generator to the edge modulation system from asecond edge modulation system upon failure of one or more components ofthe edge modulation system.
 6. The edge modulation system of claim 1,wherein the one or more modulator subsystems comprise: a modulator mediaaccess controller operable to provide non-packetized video, data andvoice information to a modulator channel coding module and packetizedI/Q data to a modulator I/Q decapsulation module; the modulator I/Qdecapsulation module operable to de-packetize the I/Q data and provideI/Q digital data to the digital modulator; the modulator channel codingmodule operable to receive data from the modulator media accesscontroller and to perform digital I/Q channel coding on the data; thedigital modulator operable to receive the I/Q digital data from themodulator I/Q decapusulation module or the modulator channel codingmodule and to perform channel shaping, and combine channels into channelblocks, the digital modulator is also operable to upsample the channelblocks and digitally modulate the I/Q digital data with a carrierfrequency and interpolate the modulated data to a sample frequency; anda digital analog converter operable to sample at the sample frequencyoperable to provide a direct analog synthesis of the output of thedigital modulator for output to a physical layer.
 7. Acomputer-implemented method, comprising: receiving incoming digital datastreams by a controller; directing the incoming digital data streams toone of one or more modulators or one or more I/Q generators by thecontroller; converting digital data contained within the incoming datastreams to in-phase and quadrature components at the one or more I/Qgenerators; receiving the in-phase and quadrature components from thecontroller at the one or more modulators; digitally combining thein-phase and quadrature components with normal service data receiveddirectly from the controller; and modulating at the one or moremodulators the digitally combined in-phase and quadrature components fortransmission over an access network; and wherein the one or more I/Qgenerators are operable to provide an I/Q generator media accesscontroller operable to provide control and processing for informationreceived from or destined for a switch in the controller, a channelcoding module operable to receive data from the I/Q generator mediaaccess controller, perform digital I/Q channel coding on the data andprovide convolutional encoding and symbol mapping for the accessnetwork, and an I/Q encapsulation device operable to packetize I/Qdigital data received from the channel coding module.
 8. The method ofclaim 7, wherein directing comprises using the switch to forward thevideo, data and voice streams to the one or more I/Q generators or oneor more modulators responsive to a packet processor.
 9. The method ofclaim 8, further comprising providing a backup interface operable at theswitch to couple an edge modulation system to an external switch. 10.The method of claim 9, wherein the backup interface facilitatesproviding a backup I/Q generator to a second edge modulation system uponfailure of one or more components of a system used in the method. 11.The method of claim 7, wherein the one or more modulators are operableto provide a modulator media access controller operable to providenon-packetized video, data and voice information to a modulator channelcoding module and packetized I/Q data to a modulator I/Q decapsulationmodule, wherein the modulator I/Q decapsulation module operable tode-packetize the I/Q data and provide I/Q digital data to a digitalmodulator, the modulator channel coding module operable to receive datafrom the modulator media access controller and to perform digital I/Qchannel coding on the data, the digital modulator operable to receiveI/Q digital data from the modulator I/Q decapusulation module or themodulator channel coding module and to perform channel shaping, andcombine channels into channel blocks, the digital modulator is alsooperable to upsample the channel blocks and digitally modulate the I/Qdigital data with a carrier frequency and interpolate the modulated datato a sample frequency, and a digital analog convertor operable to sampleat the sample frequency operable to provide a direct analog synthesis ofthe output of the digital modulator for output to a physical layer.